In the field of soil compaction, compaction devices are used in which a soil contact surface, which in most cases is formed by a flat plate or a roller body (drum), by means of an unbalance exciter is caused to vibrate, thereby exerting a pulsing compressive force onto the soil.
By means of this it is possible to achieve with simple compaction devices in the contact operation (permanent soil contact) soil compaction forces which temporarily amount to 2-times of the weight of the device. In case an occasional taking-off of the soil contact surface is permitted, even soil compaction forces can be achieved which temporarily amount to 2.5-times of the weight of the device.
In more sophisticated compaction devices, which function according to the damper principle, the plate or roller body is via a spring-damper-system connected with an damper mass arranged above it, which mass via the spring-damper-system is also excited in order to vibrate. In case the erasor mass is vibrating in phase with the same frequency (1:1 resonance) or with half of the frequency (2:1 resonance) of the plate or the roller body, with this machine concept soil compaction forces can be achieved which amount to more than 3-times of the weight of the device, if the taking-off of the soil contact surface from the ground is permitted. Such soil compaction surfaces are know e.g. from WO 2011/127611 A2.
In particular when compacting asphalt, a taking-off of the soil contact surface from the ground is however inadmissible, since such a compaction operation would result in a fragmenting of the mineral material at the asphalt surface, what at all costs must be avoided. Nevertheless, also here there exists a permanent desire for machines having increased compaction power.